1. Technical Field
Various embodiments of the present disclosure relate to an electronic device, and more particularly to a semiconductor memory device and an operating method thereof.
2. Related Art
A semiconductor memory device is one of the examples of semiconductor devices. The semiconductor memory devices may be classified into volatile memory devices and nonvolatile memory devices.
The nonvolatile memory device can retain its data even in the absence of a power source, although it may have a slow read and write speed. The nonvolatile memory device may be used for the task of secondary storage, which does not lose the data when the device is powered down. Examples of the nonvolatile memory device may include a read-only memory (ROM), a mask ROM (MROM), a programmable ROM (PROM), an erasable programmable ROM (EPROM), an electrically erasable programmable ROM (EEPROM), a flash memory, phase-change random access memory (PRAM), a magnetic RAM (MRAM), a resistive RAM (RRAM), a ferroelectric RAM (FRAM), etc. The flash memory may be classified into a NOR type and a NAND type.
Like a random access memory (RAM), the flash memory can be written and erased multiple times, and like the ROM, the flash memory can retain its data even when power is interrupted. Recently, the flash memory is widely used as a storage medium of portable electronic devices such as a digital camera, a smartphone, a personal digital assistant (PDA) and MP3.